Floor conditioner



Oct. 24, 19-67 I. JEPSOON ETAL 3,349,266

FLOOR CONDITIONER Original Filed Aug. 22, 1958 I5 Sheets-Sheet 1 Oct. 24, 1967 JEPSON ETAL FLOOR CONDITIONER 3 Sheets-Sheet 2 Original Filed Aug. 22, 1958 INVENTORS.

v z wt l. JEPSON ETAL FLOOR CONDITIONER Original Filed Aug. 22, 1958 5 Sheets-Sheet 5 INVENTORS United States Patent 3,349,266 FLOOR CONDITIONER 'Ivar Jepson, Oak Park, and Alfred F. Ernstherger, Broadview, 111., assignors to Sunbeam Corporation, Chicago, IlL, a corporation of Illinois Original application Aug. 22, 1958, Ser. No. 756,710, new Patent No. 3,068,503, dated Dec. 18,1962. Divided and this application Aug. 28, 1962, Ser. No. 219,848

Claims. (Cl. 310-247) This invention relates to a floor conditioner and, more particularly, to an apparatus for scrubbing and polishing floors and for scrubbing rugs.

Specifically, the present application is a division of co pending application Ser. No. 756,710, filed Aug 22, 1958, now Patent No. 3,068,503, granted Dec. 18, 1962.

There are several general types of floor polishers or conditioners which are known and currently used in this art. The types referred to are distinguished by the number, shape and orientation of the polishing brushes. Although some aspects of the invention have application to any type of polisher, they will be shown and described in connection with the type of floor polisher having a pair of horizontally disposed counter rotating brushes. This type of polisher is generally preferred for home use since it is small and compact in design and has the greatest stability due to the fact that the reaction effect of the brushes against the floor cancels itself as a result of the oppositely rotating brushes.

In the conventional design of this type of floor polisher, the motor, which is drivingly connected to the brushes, is positioned immediately above the brushes and substantially coextensive with them. The motor frame generally takes the form of an oval as seen in plan view (FIG. 3) with the rounded end coincident with the circular brushes. The housing or shroud for the motor is usually an inverted cup-shaped member with its lower lip in engagement with the periphery of the motor frame. The relative positioning of the motor, frame, housing and polishing brushes has placed definite limitations on the usefulness of the polisher.

Although the arrangement of the motor and housing directly above the dual brushes results in an efiicient, compast design, it has the undesirable effect of producing a polisher of substantial height which is difficult to slide under furniture and overhanging portions of cabinets and 'the like. If the motor were to be removed from its position above the brushes to reduce this height, the polisher would be much more bulky and other problems connected with protecting theelectric motor from the water ,used in scrubbing would be made more complex. For these reasons, most attempts at solving this problem have been concerned with making the electric motor as flat as possible so that the height of the motor adds as little as possible to the over-all height of the floor polisher. There are, however, obvious limitations to this approach since a fairly powerful motor is needed to drive the floor polisher and'it must, of necessity, occupy a substantial amount of space in the vertical direction. This limitation has prevented prior art -floor polishers from being constructed so that they may polish under the overhanging portions of kitchen cabinets and thelike.

"In View of the fact that most home floor polishers find most frequent use in'the kitchen, the importance of being able to polish under the overhanging edges of cabinets cannot be minimized. Since the overhang is normally less than four inches,'it would be virtually impossible to flatten an electric motor enough so that the motor would occupy so little space above the brushes that the polisher unit could be slid under this overhang. It would be desirable to provide a floor conditioner which would polish under such overhanging portions of cabinets to scrub and polish the portions of the floor thereunder. It also would be'desirable to provide a floor conditioner which would polish up to walls and which would go under tables and chairs easily. It also would be desirable in a floor conditioner to have simple and rugged motor mounting and commutator brush mounting structure along with an effective bearing structure therefor.

It is well known in the floor polisher art to provide support rollers for the polisher to adapt the unit to the scrubbing and cleaning of rugs and fabrics. In order for a floor polisher to be useful and effective in scrubbing a rug, means must be provided to regulate the force applied between thebrushes and the rug surface. It has been found that it is extremely harmful to a rug to allow the full weight of the floor polisher to urge the scrubbing brushes against the carpet surface. For this reason, the above-mentioned rollers are employed to supportpart of the-loadof the floor polisher, thereby removing some of the weight from the scrubbing brushes.

In most instances the floor polisher will be used more frequently for polishing rather than scrubbing rugs. Since these supporting-rollers, for usein rug scrubbing, are only needed by the user of the appliance infrequently, it would be desirable to have the supporting structure for these rollers as simple and compact as possible.

It is accordingly an object of the invention to provide a new and improved floor conditioner.

A further object of the invention is to provide a simplified motor and supporting frame therefor in a floor conditioner in which a single unitary casting provides the support for the armature, the motor field, the motor brushes and the gearing associated with the floor conditioner.

Yet another object of the invention is to provide a floor conditioner having a frame provided with a cradle portion for supporting the motor field which isheld on the cradle by a strap together with self-aligning bearings for the armature shaft. The bearings are mounted in gear housings in the frame and have worm gears meshing with gears on brush spindles. The bearings are held by covers of the gear box housings, and seals of elastic, grease resist-ant plastic fit into slots at ends of the housings to retain grease in the housings. Brush holders are held'in seats in the frame by single screws.

A further object of the invention is to provide a floor conditioner having a motor casing secured to the frame by spring hooks.

Other objects of the invention will become apparent from the following detailed description of a floor'conditioner forming a specific embodiment thereof, when read 1n conjunction with the appended drawings, in which:

FIG. 1 is a perspective view of a floor conditioner forming one embodiment of the invention;

FIG. 2 isan enlarged, vertical section of the conditioner shown in FIG. 1, and taken perpendicular-to the armature shaft through -'the portion including the commutator brushes;

FIG. 3 is an enlarged, plan view of the conditionerwith the motor housing and portions of brush holders andgear housing cut away; and

FIG. 4 is an enlarged vertical section taken along line 44 of FIG. 3.

The-invnetion provides a floor conditioner in which the motor and its housing are set back from the front edge of the motor frame so that the portion of the frame and brushes thereunder can be moved under :overhanging cabinets and the like. The forwardly extending portion of the frame is substantially flat and as low as possible in height. The conditioner has quickly detachable brushes and quickly detachable polishingpads. A pair of simple, adjustable supporting attachments are used to support the conditioner when used to scrub carpets. A single unitary cast frame is employed to support all the elements of the motor, the gearing, the bearings and the handle. The motor field is supported by a cradle portion of the frame and held in place by a U-shaped strap which serves to guide cooling air through the field. The covers for the gear boxes having springs for holding self-aligning bear ings in bearing seats in the frame. The covers also press molded seals of neoprene into slots in the frame to seal grease in the gear box. The motor housing is secured to the frame by leaf spring hooks firmly holding the cover on the frame.

Referring now in detail to the drawings, the floor conditioner shown therein includes a pair of oppositely driven disc brushes carried by a frame 11 and driven by an electric motor 12. The motor 12 is enclosed by means of an inverted cup-shaped housing or casing 13. This assemblage is manipulated by a handle 14. The handle 14 comprises an elongated shaft portion 15a and yoke shaped portion 15b which serves to connect the handle to the polisher frame. The yoke portion 15b is constructed from channel shaped material which is formed in the shape of a U and connected to the lower end of the shaft portion 15a by welding. The ends of the legs of yoke portion 15b are provided with means for pivotally relating the handle and the motor frame 11 as will be explained in detail below. The frame 11 is of a generally inverted cupshaped configuration having a depending peripheral flange. Frame 11 is a one-piece die-casting which serves to support all the parts of the polisher as well as providing gear boxes for the transmission means connecting the motor 12 to the polishing brushes 10.

The motor 12 is provided with a laminated iron field 16 which is supported on frame 11 by a cradle structure formed by upwardly extending supporting lugs or posts 17 and 18. The lugs 17 engage shoulders on the field 16 and positively lock the field against rotation relative to the field. The outer most lugs 18 as viewed in FIG. 4 engage the ends of the field 16 and prevent endwise movement thereof. The two more centrally located lugs as viewed in FIG. 4 have concave upper surfaces and engage the periphery of the field 16 to support it thereon.

For the purpose of holding the field fixedly in the cradle structure formed by the lugs 17 and 18, a U-shaped shroud or strap 19 is employed. The bight portion of strap 19 engages the upper semi-cylindrical portion of the field 16. The ends of the legs of the U-shaped strap 19 are provided with outwardly extending flanges 19a which are secured to frame 11 by screws 20.

The motor 12 has an armature which is mounted on a shaft 26. The armature shaft extends transversely of the frame 11 so that the ends of the shaft 26 are located above and slightly to the rear of the axes of the polishing brushes 10. To support the armature shaft bearings and the other gearing and bearings associated with the floor polisher, a gear housing 32 is cast integrally with the frame 11 and extends upwardly therefrom. The housing 32 has an outer peripheral wall 32a and a generally horizontally extending floor portion 32b. The floor portion 32b serves to define the lower wall of a chamber 32c within which the motor bearings and reduction gearing of the polisher are received.

The armature shaft 26 is supported by means of a pair of spherical or self-aligning journal bearings 27. The gear housing wall 32]) is formed with an upwardly facing spherical bearing seat 28. The chamber 320 is filled with a heavy lubricating grease and is closed by means of a cover plate which is secured to the walls 32a by means of assembly screws 31. Suitable gasketing between the cover 30 and the walls 32a prevents leakage of lubricant therefrom. The cover plate 30 not only serves as a closure for the gear chamber 320 but also mounts the means for retaining bearing 27 in position in bearing seat 28. A U-shaped leaf spring 29 has its bight portion riveted to the bottom face of cover plate 30 with its legs extending downwardly to bias the bearing 27 against its seat 28 and lock it into the bearing slot to prevent bearing rotation.

To absorb the thrust on the ends of the armature shaft and provide adjustment of the longitudinal positioning and adjustment of the play in the armature shaft 26, adjustable thrust screws 33 are threadedly received in bores 35 tapped in the walls 32a of the gear housing. The screw 33 is locked in position by means of nut 34 which is threaded thereon. The adjustment screw 33 is provided with a recess for receiving a thrust bearing 33 made of bronze or other suitable bearing material.

To permit entry of armature shaft 26 into gear housing 320, an opening 32d is formed in the wall 32a. To avoid binding or interference between the shaft 26 and the sides of opening 32d, the opening is considerably larger than the shaft diameter. A gasket or molded seal 36 is employed to seal the space between shaft 26 and the sides of opening 32d so that lubricant will not escape from the gear chamber 320. The molded seal 36 may be made of a polymerized chloroprene compound or the like resilient material. The portions of walls 32a adjacent the openings 32d are provided with slots 37 which receive the peripheral portions of the molded seals 36. The spherical bearings 27 fit tightly against the molded seals 36 deflecting them outwardly and assuring sealing engagement with the walls of slots 37. The upper edges of the molded seals 36 extend above the tops of walls 32a so that the covers 30 tend to compress the molded seals for good sealing engagement.

For the purpose of cooling the motor 12, an axial flow fan (FIG. 4) is fixed to the armature shaft adjacent one end of the armature 25. The strap or shroud 19 which was described above as retaining the field in assembled relation to the motor frame 11, also serves to direct the cooling air moved by fan 45 through the field and armature structure. To best accomplish this purpose, the semicylindrical portion of the shroud 19 is positioned close to the path defined by the ends of the blades of fan 45.

To assure axial flow of the air at the bottom of the fan which is not closely embraced by the shrould 19, the frame casting 11 is formed with a pair of integral wedge shaped projections 11a (FIG. 4). The two projections 11a cooperate to form a concave wall extending between the vertical portions of shroud 19 in closely spaced relation to the lower half of the path defined by the ends of the blades of fan 45. Thus the shrould 19 and the projections 11a define a circular opening within which the fan 45 is mounted for rotation. The fan 45, as viewed in FIG. 4, moves the air from right to left, cooling the entire motor 12.

At the right-hand end of the armature windings, there is provided a commutator 46 supplied with power from carbon brushes 47. To mount each of the carbon brushes 47 for slidable movement radially of the commutator 46, a channel shaped brass sleeve 48 is provided which is received within the plastic brush holder 51. The brush holder 51 is molded with an elongated recess 5111 which opens toward the commutator and snugly encloses the sleeve 48. To retain the sleeve 48 in assembled relation in the recess 51a the brush holder 51, a tab 53 extends outwardly from the end of the sleeve most remote from the commutator 46. The base of the recess 51a has an opening 54 extending outwardly therethrough. The tab 53 extends through the opening 54 and is bent over on the outside of brush holder 51 to prevent relative movement between the brush holder 51 and the sleeve 48.

The sleeve 48 not only provides a suitable bearing surface for the carbon brush 47 to slide upon, but it serves to retain the carbon brush assembled to the brush holder 51 and to prevent the electrical connectors from engaging the commutator as wear occurs in the brush as will be pointed out below. The electrical connections between the field coil leads and the carbon brushes 47 are accomplished by means of a pair of lead connectors 50. The outer ends of the carbon brushes are formed with cylindrical bosses 47a of reduced diameter. Each connector has a channel shaped portion 49 having side Walls 49a above and below the ends of brush. The base or center of portion 49 has a perforation to receive the cylindrical boss 47a. To assure good electrical conduction between the connector 50 and brush 47 as well as to retain the parts in assembled relation, the walls 49a of the connector 59 are bent inwardly so that they grip the end portion of brush 47. To provide clearance for the lowermost of the walls 49a, the channel shaped sleeve 48 has a longitudinally extending groove 48a in its base portion as can be best seen in FIG. 4.

To bias the brush 47 into engagement with commutator 46, a helical spring 52 is received within the sleeve 48. One end of the spring 52 seats against the bottom of the recess 51a in brush holder 51. The outer end of the spring 52 encircles the cylindrical boss 47a and is in engagement with the lead connector 50. Thus the spring 52 also biases the lead connector 50 into engagement with the brush 47.

The upper face of the brush holder 51 has a slot 56 extending through the wall to recess 51a so that there is clearance for the outwardly extending end of the connector 50 to move longitudinally of the brush holder 51. The slot 56 is coincident with the mouth of the channel shaped sleeve 48 so that the connector 50 may extend outside of the brush holder and slide longitudinally thereof as wear occurs to the brushes 47 To prevent the connector 50 from sliding completely out of the sleeve 48 and into engagement with the commutator 46 after the carbon brush 47 has worn substantially, the sleeve 48 is formed with a pair of inwardly extending stop members 55. When the brush holder 51 is not in assembled position on the motor frame or when the carbon brush 47 has been almost completely worn away, the helical spring 52 will tend to urge the connector 50 out of the sleeve 48. The stop members 55 engage the lead connector 50 and limit the action of the helical spring 52 in biasing the lead connector 50 outwardly from the brush holder.

The brush holders 51 are assembled to the frame casting 11 by means of mounting projections 57 (FIG. 3) which are molded integrally therewith and extend side- Wardly therefrom. The projections 57 have longitudinally extending slots 58 through which assembly screws 59 extend. To position the brushes on a diametrical line through the commutator, the frame 11 has a pair of upwardly extending post members 61 cast integrally therewith. Extending across the top of post members 61 are grooves 61a which are of suitable Width to snugly receive the brush holders 51. To insure positive seating at the proper height, the grooves 61a are deep enough to pro- -vide clearance between the posts 61 and the brush holders 51 while the brush holders 51 seat against the tops of posts 61 on the side projections 57 and the longitudinally extending shoulder portions 51b which extend along the length of both sides of the brush holders. Assembly screws 59 for the brush holders are received in threaded openings in the upper faces of posts 61 as can be best seen in FIG. 4. One of the screws 59 also serves to assemble a notched conductor holding clip 62 in position against the top face of one of the brush holders 51. The .clip 62 has a notch 62a in its outwardly extending end to secure one of the field leads therein to prevent its interference with the rotating member. To positively lock the brush holders 51 in a radial direction relative to the commutator 46, downwardly extending protuberances 63 are formed on the inner ends of each of the brush holders 51. Each protuberance 63 engages the inner face of post 61. The slots 58 for assembly screws 59 cooperate with the protuberances 63 to permit easy assembly and disassembly of the brush holders 51 to the frame 11. To disassemble one of the brush holders 51, its assembly screw 59 need only be loosened slightly so that the brush holder may be elevated sufficiently to disengage the protuberance 63 from the face of the support post 61. The brush holder may then be slid rearwardly away from the 6 commutator thus disengaging the side projection 57 from the screw 59.

From the above description, it is clear that armature shaft 26 is supported by means of two spaced spherical journal bearings 27 and adjustable thrust bearings 33'. The portions of shaft 26 between the journal bearings and the thrust bearings have worms 71 machined thereon. To rotatably support the polishing or scrubbing brushes 10, vertically extending shafts or spindles 73 are mounted in frame 11 immediately in front of the worms 71. To complete the gear reduction between the armature shaft 26 and brush supporting spindles 73, worm gears 72 are staked to the upper end of spindles 73 and rotate in engagement with the worms 71 on armature shaft 26.

The bottom wall 32b of the gear chamber 32c has an integrally cast bearing supporting sleeve 75 extending downwardly therefrom. Elongated journal bearings 74 are press fitted into the bearing supports 75 and support the spindles 73 for rotation therein.

To absorb the axial thrust on spindle 73 there is provided a thrust washer 77 at the brush end of the journal bearing 74. The felt washer 76 is seated in an annular recess in the bottom wall 32b of the gear chamber 320. The felt washer 76 bears against the lower face of Worm gear 72. The Worm gear and spindle assemblies are secured in place for rotation in journal bearing 74 by means of a C-ring 78 which snaps into an annular groove in spindle 73 to prevent withdrawal of the spindle shaft upwardly through the bearing 74. The thrust washer 77 is assembled between the C-ring 78 and the lower face of journal bearing 7 4.

The portion of the spindle 73 extending below the C-ring 78 is provided with flattened portions 79 which serve to key the brush 10 against rotation relative to the spindle 73. The brushes 10 have backs 80 from which the bristles extend. The backs of the brushes have assembly holes 81 formed therein which have flat sided portions to cooperate with the flattened portions 79 of the spindles 73 to prevent relative rotation between the brushes and the driving shafts.

To complete the assembly of the brushes 10 to the spindles 73 a pair of sheet metal brackets 82 are secured to the underside of the brush backs 80. These brackets lock the brushes 10 against axial movement relative to the spindles 73. The sheet metal bracket 82 resembles in form two crossed U-shaped brackets joined at their bight portions with their legs extending upwardly in spaced parallel relation. To secure the bracket to the bottom of brush back 80, a pair of legs 82a of one of the U-shaped portions is secured to the underside of the brush back by means of screws or rivets 83. The bracket 82 is further supported by a third leg 82b (FIG. 4) which fits tightly into a slot 84 in the bottom of back 8%. The leg opposite to 82b, 82c, is unsupported at its end and serves to lock the brush 80 to the spindle 73. The locking engagement between the leg 82c and the spindle 73 is accomplished through the lateral displacement of an opening 82d which is formed in a horizontally extending portion of leg 82c. The lower ends of spindles 73 have annular grooves 73a formed thereon. The opening 82d in the leg 82c is of suflicient size to receive the end of spnidle 73 when the opening and shaft are placed in alignment. The hole 82d is, however, displaced laterally from alignment with the hole 81 in the brush back 80. Thus, to bring the holes 81 and 82d into alignment, it is necessary to deflect the leg 820 by squeezing the U-shaped portion comprising leg 82b and $25. After the brush is assembled to the spindle 73 and the squeezing force released from leg 82c, it tends to deflect to its unbiased position. Under such conditions, a locking portion 82s along the edge of opening 82d snaps into the annular groove 73a to lock the brush 10 on the spindle. To remove the brush 18 from the spindle 73, it is merely necessary to deflect the leg 82c to the left as seen in FIG. 4 until the opening 82d becomes aligned with the spindle 73.

To enable the brush to be rapidly assembled to the spindle 73, a camming portion or bevel 86 is placed on the lower end of the spindle 73. The brush may then be assembled to the spindle without squeezing inwardly on the leg 82c. By merely moving the brush axially of the spindle 73, the carnming portion or bevel 86 deflects the opening 82d until it becomes aligned with the spindle 73. If the brush continues to be moved axially of the spindle 73, the opening 82d and its locking portion 82:: become aligned with the annular groove 73a at which time the locking portion 82e snaps into engagement with the groove 73a.

It is sometimes desirable to secure polishing pads to the floor polisher to be rotated by the spindles 73. To permit the most simple construction possible for the polishing pads, they have been mounted by means of merely snapping them to the face of the brushes 10. Each pad comprises I a circular polishing member 92 having a snap member 93 secured to its midpoint. The bracket 82 has a cooperaitng snap 90 secured thereto which cooperates with the snap 93 to assemble the polishing pad to the face of the brush member 10.

Mounted to the right of the frame 11, as viewed in FIG. 2, is the sheet metal housing 13 which creates an attractive appearance for the top of the conditioner and also keeps dirt away from the motor 12. A substantial amount of the left-hand portion of the frame 11, which is quite flat and low in height projects beyond the housing 13 so that it may enter the space between low overhanging cabinets and the like to scrub and polish therebeneath. As can be seen in FIG. 2, the frame 11 has been designed to occupy a minimum amount of space above the brushes 10. The substantial width of the low projecting portion of the frame 11 has been made possible by placing the motor rearwardly of the spindles 73 and utilizing a housing 13 which conforms as closely as possible to the contour of the motor.

A protective rubber or plastic bumper 95 covers the periphery of the frame 11. The bumper has a central groove which engages a ridge on the frame 11 to maintain it in position thereon. To position the housing 13 relative to the frame 11, a plurality of upwardly extending shoulder protuberances 9'5 and 97 are provided. The lower periphery of the housing 13 rests on shoulders 96a and 97a to space the sheet metal housing 13 above the metal frame 11, thereby minimizing the vibration noise which might be produced between these two members. Although some of the ventilating air is taken in and exhausted through the space between the frame 11 and the housing 13, additional air inlet slots 98 (FIG. 4) and air outlet slots 99 are formed in the housing 13. The portion of the housing coextensive with the shroud 19 fits fairly closely over the shroud so that the portions of the housing extending beyond the ends of the shroud act as extensions of the shroud in guiding air to and from the motor.

To secure the housing 13 to the frame 11, a pair of inverted U-shaped hooks 105 of spring sheet metal are employed. As can be best seen in FIG. 4, the ends of the housing 13 are engaged by hook members 105a which extend inwardly from the bight portion of each of the U-shaped hooks 105. Suitable slots 106 are formed in the housing 13 to receive the hooks 1050:. The downwardly extending legs of the U-shaped hooks each have hook shaped portions 1050 extending inwardly from their lower ends. Each end of the frame 11 has two downwardly extending openings 109 provided to receive the hook portions 1050. The inner edge of each of the holes 109 has a transversely extending rib 103 formed therein. The inner ends of the hook portions 1050 snap into assembled engagement with the ribs 108. The openings 109 have shouldered portions or recesses 110 which serve to support the portions 105d of the U-shaped hooks 105 as they are being assembled to the housing 13. The assembly hooks 105 are designed with their U-shaped so that the handle mounting means may enter the housing 13 between the legs of the U-shaped hooks. The opening or space between the legs of each of the hoops is designated :2. The portion of housing 13 adjacent each of the openings 105a is provided with a cor responding opening in alignment with and slightly larger than opening 105e for the handle mounting means to extend therethrough. To lessen the possibility of damage to the insulation on the electrical conductors which enter the housing through one of the openings 105e, the edges of the openings 1052 are provided with rolled edges 105 To mount the handle 14 pivotally on the frame 11, trunnions 121 having enlarged heads 121a are spot welded to the lower ends of the handle yoke 15b. The inwardly extending ends of trunnions 121 are formed with grooved portions 12111 which serve to locate the trunnions against axial displacement. To rotatably support the trunnions 121, the frame 11 is provided with upwardly facing bearing seats 122. The grooved portions 121b are received in the bearing seats 122 and secured therein by means of leaf spring straps 123. The straps 123 are secured in assembled relation to the frame 11 by means of screws 124. The trunnions 121 and the associated handle yoke 15b permit the handle to be rotated through an angle of slightly more than 90. As viewed in FIG. 2, the yoke 15b may be rotated to the right until it engages the frame 11. In this position with the yoke rotated down against the frame 11, the conditioner may be conveniently hung on a wall hook with the brushes against the wall. When lifted in this position, the center of gravity of the frame, motor, brushes, etc. is located in such a position to maintain the frame rotated against the yoke 15b in the convenient position for wall mounting. The upper end of the handle has a hole 126 in the back thereof to permit the hanging of handle on a nail or a hook on the wall. For storage on the floor, the handle may be moved forwardly to an overcenter position just forward of its vertical position, the limits of which are determined by raised stops 127 provided on frame 11 and engaged by the lower ends of the yoke 15b when the handle is moved to its overcenter position and not engaged when the handle is in any of its positions to the rear of this forward position.

A power cord 131 extends from a resilient grommet type strain relieving sleeve secured to the handle 14, and insulated conductors 132 of the cord travel down the hollow handle and along the inside of one leg of the yoke 15b where they are held by a cardboard retainer 133 held in the channel-like yoke by spring clips 134. The conductors are wrapped one complete turn around the adjacent trunnion before passing them through opening 10512 in one of the hooks 105 and are clamped to the frame by a clip 135 (FIG. 3). The ends of the conductors are connected to leads 136 of the motor by known means. The portions of the conductors 134 extending through the hook 105 are protected with an insulating, wear resistant sleeve. The conductors are wound around the trunnion 121 in a direction such that pivotal movement of the handle 14 rearwardly from its extreme forward position tends to unwind the conductors so that they are slackened rather than tensioned.

Although there has been illustrated and described a preferred embodiment of the present invention it will be understood that various changes and modifications may occur to those skilled in the art. It is intended in the appended claims to cover all those changes and modifications which fall in the true spirit and scope of the present lnvention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. In a floor polisher having a supporting frame, a pair of spaced vertical spindles supported for rotation on said frame, a motor mounted on said frame drivingly connected to said spindles, a commutator brush assembly for said motor comprising an elongated brush holder of insulatmg material extending radially of the axis of said motor, a longitudinal. recess in said brush holder having its mouth toward said motor, a commutator brush slidably mounted in said recess, said brush having a shouldered portion at its outer end and a cylindrical boss extending therefrom, a helical spring mounted in said brush holder with one end engaging the bottom of said recess and the other end receiving said cylindrical boss, a brush connector having a lead connecting portion and a brush contacting portion, said brush contacting portion having an aperture therein for receiving said cylindrical boss, and a longitudinally extending clearance slot in said holder for said connecting portion to extend outwardly from said recess, said spring biasing said contacting portion into engagement with said shouldered portion.

2. In a floor polisher having a supporting frame, a pair of spaced vertical spindles supported for rotation on said frame, a motor mounted on said frame drivingly connected to said spindles, a commutator brush assembly for said motor comprising an elongated brush holder of insulating material extending radially of the axis of said motor, a longitudinal recess in said brush holder having its mouth toward said motor, a commutator brush mounted in said recess, said brush having a shouldered portion at its outer end and a cylindrical boss extending therefrom, a helical spring mounted in said brush holder with one end engaging the base of said recess and the other end receiving said cylindrical boss, a brush connector having a lead connecting portion and a brush contacting portion, said brush contacting portion having an aperture therein for receiving said cylindrical boss, a longitudinally extending clearance slot in said holder for said connector to extend outwardly from said recess, said spring biasing said contacting portion into engagement with said shouldered portion, and a channel shaped metallic member received in and coextensive with said recess for slidably supporting said commutator brush therein, the open edge of said channel being aligned with said clearance slot.

3. A floor conditioner as set forth in claim 2 wherein said brush holder has an outwardly extending opening in the bottom of said recess, and an assembly tab on said channel shaped member protruding through said opening an-d being bent over to retain said member in assembled rotation to said brush holder.

4. A floor conditioner as set forth in claim 3 wherein said channel shaped end of said open edge to enga-ge said connector and prevent said helical spring from biasing said connector out of said brush holder.

5. A floor conditioner as set forth in claim 2 wherein said brush contacting portion of said connector is U-shaped with the legs of said U being resilient and gripping the end of said commutator brush.

6. In a brush holder of the type comprising a generally rectangular hollow body member open at one end and closed at the opposite end and adapted to contain a carthrough the slot and electrically connected to the carbon brush between the brush and the spring is retained in the holder upon removal of the brush as a result of said terminal end being resiliently held against the end of said slot adjacent the open end of the holder by the spring.

7. In a brush holder of the type comprising a generally rectangular hollow body member open at one end and closed at the opposite end and adapted to contain a carbon brush which is resiliently urged outwardly through the open end thereof by a spring seated wholly within said body member between the closed end thereof and the inner end of the brush, the improvement which comprises, a slot formed in one side of the brush holder intermediate the ends of said one side whereby to permit a conductor terminal member to be inserted through the slot and electrically connected to the carbon brush for outward movement therewith, the end of said slot adjacent the open end of the holder serving to retain the terminal member within the body member upon removal of a worn carbon brush therefrom.

8. In a brush holder assembly having a hollow brush holder with a closed rear end and an open front commutator end, a carbon brush slidably mounted therein, and a spring member disposed wholly within the holder and seated between the closed rear end thereof and the rear end of the carbon brush whereby to resiliently urge the brush forwardly through the open end of the holder, the combination of, a slot formed in a side wall of said holder and extending inwardly from the open front end thereof, a lead-in wire insertable through said slot electrically connectable to said brush for movement therewith, and a guard member extending across the open front end of said slot for engagement by said lead-in wire whereby to retain said lead-in wire in said holder upon removal of said brush therefrom.

9. In a brush holder assembly for a rot-ary electric motor, the combination with an insulated carbon brush holder having a bore close-d at one end to receive and form a seat for one end of a spring, a carbon brush slidably mounted in said bore and having an inner terminal portion adapted to be engaged by the other end of said spring in yieldable spring-pressed relationship tending to urge said brush out of said bore, said holder having a slotted portion along one side thereof extending inwardly from its open end for a distance approximately the length of said brush, and an electrical conductor having a terminal portion insertable through said slotted portion into co operating electrical connection with said terminal portion of said brush and clampingly held thereto by said spring, of guard means on said holder and extending across said slotted portion adjacent the open end of the holder whereby to retain the terminal portion of said conductor within said holder upon removal of said brush therefrom.

10. In a brush holder assembly for a rotary electric motor, the combination with an insulated carbon brush holder having a bore closed at one end to receive and form a seat for one end of a spring, a carbon brush slidably mounted in said bore and having a reduced-in-size inner terminal portion adapted for engagement by the other end of said spring in yieldable spring-pressed relationship tending to urge said brush out of said bore, said holder having a slot along one side thereof extending inwardly from its open end for a distance approximately the length of said brush, and an electrical conductor having an I-shaped terminal member Wider in one dimension than the width of said slot but extendable therethrough in another plane into cooperating electrical connection on said terminal portion of said brush and clampingly held thereto by said spring, of a guard member on said holder and extending across said slot at the open end of the holder whereby said terminal member is resiliently held against said guard member by said spring and retained within said holder upon removal of said brush therefrom.

References Cited UNITED STATES PATENTS 1,550,102 8/ 1925 Schlueter 15-49 X 1,767,322 6/ 1930 Snyder 15-98 1,909,338 5/1933 Dulin 15-49 1,927,226 9/1933 Woods 15-50 2,258,165 10/1941 Sassano 15-49 2,683,826 7/ 1-954 Staak 310-239 X 3,075,009 1/1963 Roe et al 310-239 3,087,081 4/1963 Apostoleris 310-247 X 2,683,884 7/ 1954 Kohl 15-49 CHARLES A. WILLMUTH, Primary Examiner. R. L. BLEUTGE, Assistant Examiner. 

6. IN A BRUSH HOLDER OF THE TYPE COMPRISING A GENERALLY RECTANGULAR HOLLOW BODY MEMBER OPEN AT ONE END AND CLOSED AT THE OPPOSITE END AND ADAPTED TO CONTAIN A CARBON BRUSH AND A SPRING FOR RESILIENTLY URGING THE BRUSH OUTWARDLY THROUGH THE OPEN END OF THE BODY MEMBER, THE IMPROVEMENT WHICH COMPRISES, A SLOT FORMED IN ONE SIDE OF THE BRUSH HOLDER INTERMEDIATE THE ENDS OF SAID ONE SIDE WHEREBY THE TERMINAL END OF A CONDUCTOR EXTENDING THROUGH THE SLOT AND ELECTRICALLY CONNECTED TO THE CARBON BRUSH BETWEEN THE BRUSH AND THE SPRING IS RETAINED IN THE 